Fabrication of YBCO Films on SrTiO3 and Textured Ag Substrates by TFA-MOD Method

In this paper, we presented the results of YBCO films deposited epitaxially on both SrTiO₃ single crystal and textured Ag substrates by a TFA-MOD method. The growing conditions and forming mechanisms of the YBCO films on these two kinds of substrates was investigated systematically. It was found that the precursor film coated on Ag substrate took less time to completely decompose to an amorphous precursor film during the first stage of the calcination than that on SrTiO₃ substrate. Moreover, the higher temperature was needed to obtain pure YBCO phase on Ag substrate during the second annealing stage. A possible growing mechanism for this difference was described. A transport j_c value of 1.5 x 10⁴ A/cm² (at 77 K) was obtained for the YBCO film deposited on Ag substrate, while the film on SrTiO₃ substrate exhibited an a T_c onset of 92 K and a high j_c value of 2.3 MA/cm² at 77 K in self-field was measured.